Loom tension control apparatus



United States Patent [72] lnventor Frederick L. Sprague 2,609,007 9/1952 Beall 139/100X Hopedale, Massachusetts 2,81 1,176 10/1957 Mangum 139/304 211 Appl. No. 789,276 2,820,485 1/1958 Selles 139/99 [22] Filed Jan. 6, 1969 3,265,094 8/1966 Baird 139/1 [45] Patented Aug. 25, 1970 3,373,773 3/1968 Blaentine et a1... 139/1 [73] Assignee North American Rockwell Corporation 3,433,430 3/1969 Sprague 139/1 10X Pittsburgh, Pennsylvania FOREIGN PATENTS 19,550 1 9o6 Great Britain 139/99 1,013,744 12/1965 Great Britain 139/304 [54] LOOM TENSION CONTROL APPARATUS 1,018,409 1/1966 Great Britain 139/304 5 Claims, 5 Drawing 8 Primary Examiner- James Kee Chi 521 US. Cl 139/1, P Bronaugh 139/99, 139/304 l [51] Int. Cl D03d 49/06, D03d 49/20 of Search 1 i0, A tension Control apparatus including means for 304-403 selectively controlling the linear rate of warp yarns fed into a loom with cooperating mechanisms for maintaining automati- [56] References C'ted cally a predetermined amount of tension on the warp yarns UNITED STATES PATENTS and fabric formed thereby in the weaving area through to the 2,421,539 6/1947 Clarke 139/1 wind-up of said fabric.

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Patented Aug. 25, 1970 Sheet INVENTOR FREDE LSPRAGUE.

ATTORNEY Patented Aug. 25, 1970 Sheet 2 of 2 INVENTOR FREDERICK LSPRHGUE I MM 4% ATTORNEY.

LOOM TENSION CONTROL APPARATUS BACKGROUND OF THE INVENTION The invention relates to looms of the type for weaving a fabric such as tire cord wherein only a sufficient number of picks are inserted therein to serve as a binder for maintaining the desired separation of the warp yarns as well as keeping them in parallel alignment during the process stages of preparing said fabric for its intended purpose.

When weaving a fabric such as tire cord, an important factor is that of maintaining proper tension on the warp yarns and fabric formed thereby throughout the complete weaving process as well as holding said fabric as close to its woven width as is possible during take-up and wind-up thereof.

In known loom attachments for weaving tire cord fabric mechanisms are provided which control the linear rate of feed of warp yarns to a loom as well as for governing the rate of speed at which the woven fabric is taken up or advanced for wind-up on a cloth roll.

With the known weaving devices there is no positive means provided for maintaining a desired tension on the warp yarns and fabric in the weaving area. As is well known to those con versant in the art, the take-up roll, which is positioned at the upper front portion of a loom is driven in a positive manner such as by a train of gearing or the like Should a change develop in the rate of speed at which the warp yarns are being introduced relative to the speed at which the take-up roll is advancing the woven fabric, the tension on said warp yarns and fabric will be caused to become greater or less than desired. An increase in tension is considered quite serious for in this event the fabric is caused to contract to the extent of becoming what is considered as substantially less than the woven width which is always attempted to be maintained in the production of this type of fabric. Likewise should the tension on the fabric increase in the area between the take-up roll and the wind-up mechanism, contraction of the fabric will be introduced with similar results.

A decrease in tension on the warp yarns and fabric in the weaving area can be very detrimental to the fabric, for during the finishing thereof rubber is bonded to the surfaces of said fabric and then sheared to a specific thickness. If during the period of a decrease in tension on the warp yarns, certain of said yarns should drop below the level of adjacent yarns, they will be displaced when the rubber is bonded to the fabric surfaces. During the shearing process such displaced yarns are sheared off making that particular cut of fabric unfit for its intended purpose.

The tension control apparatus according to the instant invention provides an improved means for weaving tire cord fabric and its main object is that of eliminating the above disadvantages by providing mechanisms for maintaining automatically a constant amount of tension on the warp yarns and fabric formed thereby in the weaving area as well as in that area of said fabric which extends from the take-up to the windup mechanisms.

SUMMARY OF THEINVENTION The present invention utilizes three separate and cooperating electrical motor drive units each of which includes a control that is housed in a single control box common to each of said drive units.

The first motor drive is of the adjustable speed type and being correlated to the speed of the loom is adapted to control the linear rate of speed at which the warp yarns are fed into a loom. The second motor drive unit controls the means for rotating the take-up roll and the third the means for rotating the cloth roll upon which the fabric is wound. The controls for both the second and third motor drive units include a means for varying the speed of the motor shafts and being interconnected with the take-up roll and cloth roll respectively, they utilize changes in motor loading to continuously sense and control the speed of said motor drive units to maintain a preset fabric tension level.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a loom and the cooperating mechanisms for weaving tire cord fabric showing applied thereto the three separate and cooperating electrical motor drive units comprising the means according to the invention for maintaining a desired tension level on the warp yarns and fabric formed thereby.

FIG. 2 is a perspective view of a portion of the mechanism in FIG 1 showing on a slightly larger scale the electrical motor drive unit for controlling the feed of warp yarns to a loom.

FIG. 3 is a view similar to that of FIG. 2 but showing the motor drive unit for controlling rotation of the take-up roll.

FIG. 4 is also a view similar to FIG. 2 but showing the motor drive unit for controlling wind-up of the woven fabric, and

FIG. 5 is a view in diagrammatic form showing by means of indicating arrows the direction of travel the warp yarns and fabric are caused to travel during the weaving process.

DESCRIPTION OF THE PREFERRED EMBODIMENT Now referring to the figures of drawing, the loom shown in FIG. 1 which is identified generally by numeral 10 is of conventional design and is not illustrated in its entirety for it is believed enough of the loom and cooperating mechanisms for weaving tire cord fabric have been shown to serve as a basis for a detailed description of the invention.

Rearwardly of the loom 10 and in relatively close proximity therewith there is provided a warp compressor unit having spaced side frames 11 (left hand only shown in FIGS. 1 and 2) which are interconnected adjacent their lower ends by rear and front girt members 12 and 13. A pair of warp yarn delivery rolls l4 and 15 traverse the distance between the side frames 11 and are supported for rotation at the upper ends of the latter on shaft members 16 and 17. These shaft members are journaled in suitable bearing members (not shown) and the ends thereof shown in FIGS. 1 and 2 extend outwardly beyond the left hand side frame 11 and support a pair of spur gears 18 and 19 that are disposed in meshing relation.

The delivery rolls l4 and 15 are supported in close proximity with the forward roll 15 being supported at a higher level than its companion roll 14.

An electrical motor drive unit 20 provides the means for rotating these delivery rolls and is supported by a motor stand 21 that is attached by any suitable means (not shown) to the side frame 11 (FIGS. 1 and 2). This drive unit 20 is of the adjustable speed type and includes a motor pinion (not shown) that is disposed in meshing relation with spur gear 18.

A control station 22 (FIG. 1) is positioned on the forward left hand side of the loom and serves to house the required electrical components for providing power to and control of the motor drive unit 20 as well as the motor drive units for the take-up and wind-up of the fabric which hereinafter will be described in greater detail. A length of conduit 23 (FIG. 1) extending between the motor drive unit 20 and the control station 22 contains the necessary wiring to operate and control said motor drive unit. This drive delivers the warp threads to the loom at a constant linear rate correlated to the speed of the loom for the laying in of the preferred number of picks per inch. By simply turning a control knob 24 in one direction or the other the desired speed of the motor drive unit is obtained.

The warp yarns are depicted in FIG. 1 by numeral 25 and as well known to those conversant in the art are drawn from a suitable source of supply (not shown) such as creels or a multiple of warp beams. As shown in FIG. 5, the warp yarns as they are received from their source of supply pass over the top and around the forward portion of the delivery roll 15 thence around the rearward and lower portion of roll 14 from which they extend to the loom in a substantially horizontal plane.

The warp yarns pass through a common type of stop motion (not shown) and thence through the harnesses one of which is shown and identified in FIG. 1 by numeral 26. Weaving of the warp yarns is conventional, that is to say the reciprocating harnesses form the sheds through which a shuttle 27 is caused to travel for laying in picks of filling yarn.

The fabric as it is formed is drawn toward the front of the loom by a take-up roll partially shown and depicted in FIGS. 1 and 3 by numeral 28. The take-up roll is supported for rotation in the conventional manner at the forward and upper portion of the loom and in place of the usual gearing for rotating said roll a separate electrical motor drive unit generally indicated by numeral 29 is provided for that purpose.

The motor drive unit 29 is supported by a motor stand 30 that is fixedly attached to a right hand cloth roll stand 31 by any suitable means (not shown). This motor drive unit is located below the take-up roll 28 and includes a gear box reducer 32 on which a driving sprocket 33. partially shown in FIG. 1, is mounted. The take-up roll 28 adjacent its end includes a sprocket 34 fixed thereon which is in vertical alignment with the driving sprocket 33. An endless driving chain 35 (FIGS. 1 and 3) passes about the sprocket 34 on the take-up roll and interconnects the latter with the driving sprocket 33 that is caused to be rotated by the gear box reducer 32 which forms a part of the motor drive unit 29.

This motor drive unit provides the means for actuating the take-up roll 28 and includes a cooperating control unit whereby the fabric as it is advanced by said roll is guided and drawn under a predetermined amount of tension.

A length of conduit 36 (FIG. I) interconnects the motor drive unit 29 with the control station 22 and contains the necessary wiring to operate and control said drive unit by means of a manually operable knob 37 situated on the upper surface of said control station. Knob 37 forms a part of the control unit that is housed within the control station 22 and includes a means for varying the speed of the motor drive unit shaft (not shown) and through the gear box reducer that is interconnected with the take-up roll 28, the mechanism utilizes changes in motor loading to continuously sense and control the motor speed to maintain a preset fabric tension level.

Additionally the motor drive unit 29 includes a phase shifting function which permits the drive to run continuously at any speed down to and including stalling without creating any excessive heating up of the motor. The latter feature is particularly advantageous in the event of a loom stop for any progressive increase in fabric tension will cause a cessation of the driving elements and when the loom is ready to resume normal operation, the increased fabric tension will be relieved and the take-up roll will automatically commence rotating to advance the fabric.

The fabric is identified in FIGS. 1 and 5 by numeral 38 and as shown diagrammatically in FIG. 5, said fabric is advanced by the upper, forward and lower surfaces of the take-up roll 28 and is then directed generally rearward where it passes about a pressure roll 39. From the pressure roll 39. the fabric 38 is directed forwardly over the forward surface of a guide roll 40 thence downwardly and about the lower and rearward surface of a lower guide roll 41. The fabric is then caused to move in a horizontal plane beneath a weavers platform 42 (FIG. 1) to a wind-up guide roll 43 that directs said fabric to the independently controlled wind-up mechanism now to be described.

This wind-up mechanism is indicated generally in FIGS. 1 and 4 by numeral 44 and includes a pair of aligned frame members 45 and 46 disposed in spaced relation. Tie rods 47 (one only shown in FIG. 1) interconnect frame members 45 and 46 adjacent the lower foot portions thereof and the upper ends have fixed thereon upwardly directed and aligned frame extensions 48 and 49 respectively.

Above the tie rods 47 the frame members support for rotary movement a horizontally disposed driven roll 50 (FIG. 4) or what may be termed a fabric advancing and tension sensing roll. This driven roll is caused to rotate by means of an electrical motor drive unit generally indicated by numeral 51 which is like the drive unit 29 for the take-up roll and is caused to function in a like manner as will be described. A second driven roll 52 is supported for rotary movement by the frame members 45 and 46 and is positioned in close proximity with and immediately forward of the driven roll 50 so that the axis of one roll extends in parallel relation to the other.

A wind-up roll or so-called cloth roll 53 (FIG. I) is adapted to be supported by the adjacent upper surfaces of the driven rolls 50 and 52 and the ends of said cloth roll are adapted to be guided for vertical movement in track elements 54 and 55 which form a part of the frame extensions 48 and 49 respectively. These track elements 54 and 55 are formed by vertically disposed bar members 56 and 57 positioned forwardly of the frame extensions 48 and 49 and in spaced relation thereto.

The ends of the driven rolls 50 and 52 are shown in FIGS. I and 4 extend outwardly beyond their supporting journal points in the frame member 45 and have fixed thereon sprockets 58 and 59 respectively which are interconnected by an endless driving chain 60. The end of the driven roll 50 extends outwardly a greater distance than that of roll 52 and has fixed thereon an additional sprocket 61 (FIG. 4).

An endless driving chain 62 passes about sprocket 61 and interconnects the latter with a driving sprocket (not shown) that is caused to be rotated by a gear box reducer 63 which forms a part of the motor drive unit 51.

This motor drive unit 51 is supported by a motor stand 64 that is fixedly attached by any suitable means (not shown) to the side of the frame member 45. A length ofconduit 65 (FIG. I) interconnects the motor drive unit 51 with the control station 22 and contains the necessary wiring to operate and control said drive unit by means of a manually operable knob 66 situated on the upper surface of said control station. Knob 66 forms a part of the control unit that is housed within the control station 22 and serves as a means for varying the motor drive unit shaft (not shown). Through the gear box reducer 64 which is in driving relation with the driven rolls 50 and 52, the mechanism. like that for the take-up roll, utilizes changes in motor loading to continuously sense and control the motor speed to maintain a preset fabric tension level.

As shown by the indicating arrows in FIGS. 4 and 5 the driven rolls are caused to rotate in an anticlockwise direction and the cloth roll 53 being in frictional contact with the adjacent upper surfaces of said driven rolls is caused to rotate in a clockwise direction as viewed in said FIG. 5. In this FIG. 5 the fabric is shown to move about the lower surface of the wind-up guide roll 43 and is thence directed generally upward about the forward surface of the fabric advancing and tension roll 50. The fabric after leaving roll 50 is caused to be wound upon the cloth roll 53 which as heretofore described is caused to rotate by means of its frictional contact with the driven rolls 50 and 52. Like the motor drive unit 29 for the take-up roll 28, drive unit 51 also includes a phase shifting function that permits the drive to run continuously at any speed down to and including stalling without creating any excessive heating up of the motor.

In operation the three separate and cooperating electrical drive units can be controlled independently or together and caused to function forwardly or in reverse by the control station 22 located at the forward left side of the loom. These three drive units are tied in with the 12 volt loom stop motion circuit and once weaving begins said three drives start and stop with the loom.

The adjustable speed electrical motor drive unit 20 of the warp compressor unit is set to deliver the warp yarns 25 to the loom at a constant linear rate correlated to the speed of the loom for laying in the desired number of picks per inch.

The electrical motor drive units 29 and 51 which control the take-up roll and cloth roll respectively set the tension in the fabric. Should a lesser or additional number of picks per inch be desired it is only necessary to change the selective adjustment means for the electrical motor drive unit 20 to coincide with the number of picks desired. In this event, it is not necessary to change the settings of the drive units 29 and 51 for these drives sense the change in tension and automatically compensate to maintain fabric tension.

Additionally, the electrical motor drive unit 29 that drives the loom take-up roll 28 for regulating warp yarn and fabric tension within the weaving area also serves as an anchor in the system and prevents any disturbance of the fell line when the drive unit 51 for the wind-up is reversed or when a roll of fabric is doffed.

The three separate electrical motor drive units are of the type such as that furnished by the Vee-Arc Corporation which is located at 50 Milk Street in Westboro, Massachusetts.

lclaim:

l. A tension control apparatus for a loom adapted for independent control of warp yarn and fabric tension during the complete weaving process which comprises:

a. a pair of horizontal and adjacently disposed warp yarn delivery rolls;

b. an independent selective drive control means for rotating said delivery rolls;

c. a fabric take-up roll;

d. an independent driving member for rotating said take-up roll;

e. a fabric wind-up mechanism having a cloth roll for receiving said fabric;

f. a pair of juxtapositioned and horizontally disposed rotatable rolls for supporting said cloth roll; and

g. a further independent driving member for rotating said rotatable rolls.

2. The tension control apparatus according to claim 1 wherein said independent selective drive control means defines an adjustable speed motor correlated to the speed of the loom for controlling the linear rate of warp yarn being fed to said loom.

3. The selective drive control means according to claim 2 wherein said adjustable speed motor includes a control means for selectively determining the number of picks to be inserted into the sheds formed by warp yarns.

4. The tension control apparatus according to claim 1 wherein said independent driving member defines an electrical motor drive and a control unit therefor that is influenced by changes in warp yarn and fabric tension to effect reductions in speed of said take-up roll down to a cessation thereof upon indication of progressive increases in tension and to effect increases in speed thereof upon indication of progressive decreases in the tension of said warp yarns and fabric.

5. The tension control apparatus according to claim 4 wherein said further independent driving member defines an electrical motor drive with a control element therefor that is influenced by changes in fabric tension between said take-up roll and wind-up mechanism to effect reductions in speed of said rotatable rolls down to a cessation thereof upon indication of progressive increases in fabric tension and to effect increases in speed thereof upon indication of progressive decreases in fabric tension. 

